*{
    margin: 0;
    padding: 0;
}
#content{
    height: 9000px;
    margin: 0 auto;
    width: 100%;
    background-color: lightblue;
}
#level{
    height: 25px;
    width: 280px;
    margin: 0 auto;
    padding-top: 20px;

}
#level button{
    height: 25px;
    line-height: 25px;
    width: 60px;
    text-align: center;
    background: rgb(74, 139, 141);;
    color: white;
    padding:0px;
    margin: 0px;
    border: 0px;
    border-radius: 5px;
    outline: none;
    cursor: pointer;
}
#level button.active{
    background: #0bb9b6;
}
#level button.big{
    width: 80px;
}
#gameBox{
    padding-top: 20px;
}
#bottomText{
    padding-top: 20px;
    height: 20px;
    width: 200px;
    margin: 0 auto;
    line-height: 20px;
    text-align: center;
}
/* .mineNum{
    height: 20px;
    width: 50px;
    
} */
table{
    border-spacing: 1px;
    background-color: #929196;
    margin: 0 auto;
}
td{
    height: 20px;
    width: 20px;
    background-color: #ccc;
    padding: 0;
    border: 1px solid;
    border-color: #fff #a1a1a1 #a1a1a1 #fff;
    text-align: center;
    line-height: 20px;
    font-weight: bold;
}
.mine{
    background:#c9c9c9 url(../images/boom.png) no-repeat center;
    background-size: cover;
}
.flag{
    background:#ccc url(../images/flag.png) no-repeat center;
    background-size: cover;
}
td.zero{
    background-color: #d9d9d9;
    border-color: #d9d9d9;
}
td.one{
    color: red;
    background-color: #d9d9d9;
    border-color: #d9d9d9;
}
td.two{
    color: green;
    background-color: #d9d9d9;
    border-color: #d9d9d9;
}
td.three{
    color: yellow;
    background-color: #d9d9d9;
    border-color: #d9d9d9;
}
td.four{
    color: blue;
    background-color: #d9d9d9;
    border-color: #d9d9d9;
}
td.five{
    color: blueviolet;
    background-color: #d9d9d9;
    border-color: #d9d9d9;
}
td.six{
    color: brown;
    background-color: #d9d9d9;
    border-color: #d9d9d9;
}
td.seven{
    color: cadetblue;
    background-color: #d9d9d9;
    border-color: #d9d9d9;
}
td.eight{
    color: coral;
    background-color: #d9d9d9;
    border-color: #d9d9d9;
}
img {
            /* display: block; */
            width: 100%;
        }

        @keyframes snow {
            0% {
                background-position: 0 0, 0 0;
            }

            100% {
                background-position: 500px 500px, 1000px 500px;
            }
        }

        #snowMask {
            position: fixed;
            left: 0;
            top: 0;
            width: 100%;
            height: 100%;
            background: url('../images/snow1.png'), url('../images//snow2.png');
            animation: 10s snow linear infinite;
            /* linear速度不变   infinite无限循环 */
            pointer-events: none;
            /* 鼠标事件失效，穿膜 */
        }